Drill tool telemetering systems



Oct. 22, 1957 B. s. EATON ErAL DRILL TOOL TELEMETERING SYSTEMS 2 Sheets-Sheet 1 Filed March 25, 1952 'United States Patent() DRILL T 015i Bourne.` G. Eaton,` San .Diego, .axdwlWilliamt W Boynton;

La Canada,` Califfrassignorsfto The-Physics Corporati'on, La Canada, Calif., 'a corporation.,of-.C'alifornia Application March 2s, 1952, serial Nef-2733162?,

6 Claims... (Cl.l2ss1)- driller, geologist-,or petroleum*engineer,"for"example, at' Y the surface to haveat hand information regarding what' is taking place `at the Abottornofzthe welll y This infrmation, however, should be' madeavail'abl'e jat'z'the surface without interruption ofthe drilling process and prefer# ably without any `special communication line-from-the` bottomot thewellto thetopthereofp".

Amongtlie objects oftli'epresent' inventionarei'- To provideafm'eansf andi method hvof lobta'ining -desired information from' the bottom" oi"'a "wellduring a normal drilling operation;` using; only thefcusto'mary drill Vtool string as 'anjinfrmationtransmission liie.' i To providefan acousticalimeans' andlmethodofatrans mitting information from`1the;bottom to the top of fa. welll during the drillingoperation.' Y

To provide an acoustical" ge'r-ieratorthat lcan. be. positioned at' thepbottorr ofa well being; drilled, energized-`V solely by energ"y.nor'mall'y,'availabley at fthe.bottom. oflthe. well during"diilli`ng, together witli meansat the surface. of the ground for receiving the. output ofthefgenerator.

To provide an' acoustical oscillto'n 'that canbe.posi. tioned at or near the bottom off'a `drill ftool. string.in-the` drill string andwhich'isV energized solely by energy/available at saidposition .during a normal drilling operation'.l

To` provide such an acoustical. oscillator modulated byT at condition existing at or near the bottom oflthe=wellV duringV drilling." Y

Toprovide an.l acoustical transmitter. at .tlie.. bottomiV ofta Well, witl`1"anacoustical receiver..arthe-topfof the` well, with the transmitter modulatedf'by alconditionexisrtingV at the bottom' of, the `well whereby th'erlr-illinglcrewr or others can beV continuously.` conversantv with.. the value,-` of said"..condition throughout awellf drilling .operation= And, .to provide a simple means and `methodofobtainA ing informationfrom the bottom-.offa well'` asitis-beingr drilled. As pointed out, above; it is .very` desirable fort' the drillingcrew ofa wellv .to know, duringnhefdrfilling of'tliewelLf as much information as possible as to-condiiA tions .existing ,i atv the bottomof: the' well'.` VSuch conditions' may include temperature, 'drill pipe torque, arnountoii mud flow,- type of rock being. encountered,- forf example, and manyk others. Many.: complicated expedients have been heretofore proposedWforlthis purpose; butahavei iii-- volved departures-fromthenormali-drill v.tool stringsorf complicated `devices installed inuthevdrilly tool-string-forff recording the c onditionslocally, the-recording'snot being-f availableuntiLthe ydrill= toolllstring. ist` withdrawn'iromt the' well.

Inthepresentfapplication a'f'normal drill' :tool stn'ngisi usedw as `meaning'a'fpluralityl fof: connected hollowIk drill#AV ICC 2 offth'e string being rotated from-the ground level: Mud under pressure is suppliedtothe interior of the drill pipe stringthi'ough Aaswivel,` this mud emergingfat the tool end Aofthe string and passing upwardly on thetoutside'of tlie drill pipe toreach the surface again; Thefunction ofthe mud'to removeV 'drilling' chips and `to weight the hole'is well known'intheart: For thepurposes of the present invention; itis' immaterial whetherfthe hole is' cased ornot p Briefly; thepresent; invention A'includes the use of 'one or '-more acoustical receivers' 'attached to '.the' drill pipe string ator abovethe .ground surfaceg'withzthe electrical outputta'keni oilfthe. drill pipe `throug'hbruslie's or. the like.

The output; of the receiver or"rec`eivers`is then prefer ably` passed throug'hone or -more' frequency discriminator'sfor"isolators',' orinoise spectrum analyzers, the output, thereof: being indicated as by'level meters or by listening. witl`1`"tl1`e,`ear." Thefrequencies indicated can range from lO0`fto"l0O',00'0 .,cycl'esz p e'r second. for example. l

Normally, and; particularlyiin deepfwells, during ,drill-4 ing," tlieacoustical` noise' arriving at acoustical receivers positioned ab'vebgrjoundfon the drill'l pipe string cannot.` pos'sibly`beidentid' as .originating from any particularsource'." Even when gear type drilling bits are used, the. tooth. noise, which'can be expected tov have a-.frequency asde'terminediby the number of ground-tooth contactsv andthe R4 P. M'. of the drill pipe string,.is wholly lostand masked in other noise caused by the-table, the swiveL. and the rubbingothe drill'pipe, string-against. the-walls ofthe well; cased `or uncased, for example.

For the drillmpipe only-to be usedas .an acoustical line for" the transmission of `informationfrom -thefboth tom' to the ,top 'o "a' well-during1 drilling (rotation of itliev drill pipe' string) itis. highly desirablethatatf least one.` acoustical frequency travelling upfthevdrillr pipe bev ac# centua'tedto the point where. it can readily. be `identified; picked up, and measured at! thetopzof the string. Infaccordance with the present inventionVthisHis .done'byV the use of an acoustical oscillator positionedpreferably-justA above -the drilling.tool,together with-.means `for energiz-f` ingthis oscillatorifrom a sourceofM energy already avail-f able at the bottom Vof thewell.n

And there are several. sources oi energy availablelat the bottom of the oil, string. For example, the drillpipe-is rotating with respect to the-wall of the well, the-"mud is'V circulating downwardly ori-theA insideo-thefdrill pipe and` upwardly on the outside ofl this pipe, and vvhengeartypeI drill bits are used,the gears are rotating when in contact with the bottom of -the well'to provide a known local frequency..

Our invention Ywillube more -fully understood rin'allof its aspects Yby a perusal of the following description of` the appendeddrawings in which:

Figure 1 is a perspective diagram of a rotary drillingA rig showing, however', only thoseparts entering into the present` invention. A

Figure-2 isy alvertical sectionaly View through oneforml` of.acoustical-hoscillator operated by mud flow useiuli'in! practicing `the present invention. v

Figure alis-irafdiagramnatic perspective view of a torque i sensingdevice that canbe used to modulate the device of:VE FigurevZ. Y

Figure 2b is a fragmentary elevational lviewftakenas'. indicated-by-theline2b-2 inV Figure 2a;

Figure 3 ista'vertical sectional view Aoffa form'of acousf'- tical oscillator operated by drag.

Figure'4`is1fa vertical secti'onal'view of an acoustical oscillator operated by local'nois'e and/or irregularrota# tionalmotionsof the drill bit- Y Referringlirstto Figure" l, which shows /very diagrar'n maticallya=drillfrig^set up,"a'fdrilling tool10fis positioned at the bottom of a string of hollow drill pipe 11 extending from the ground level G to the tool 10. The string is driven through a kelly (not shown) by power, to rotate the pipe. Drilling fluid, usually called mud, is'supplied under pressure to the interior of the pipe 'through a swivel 12 positioned above the kelly. Between the kelly and the swivel, a split drum 15 is positionedvaround the drill pipe 11 and clamped solidly thereto by'bolts 16.

Mounted on drum 15 is a longitudinal vibration pickup 18 which may be of the crystal or suspended weight type, for example, and a lateral vibration pickup 19 of the same type. Leads 20 and 21 from the respective pickups 18 and 19 are brought out through slip rings 22 on the drum 15 and cooperating brushes 23 attached toa brush frame 24 attached to swivel 12.

In order, for example, for relatively narrow bands of frequencies within the range of from 100 to 100,000 cycles to be examined, leads 20 and 21 from the pickups in each case are brought into a wide band amplifier 25, the output of which is presented to a plurality of narrow band filters F1 to Fn, inclusive. The output of each filter in the group is then applied to a frequency meter Mr-Mn and/or through leads Li-Ln to other indicators such as, for example, cathode ray tubes or recorders. In addition, if desired, the wide band output of amplifiers 25 can be applied to panoramic spectrum display devices so that the entire wide band of picked up frequencies can be seen at once, such-a device being well known in the art.

It will thus be apparent that within the range of ampliers 25 all transverse and longitudinal frequencies existing in the drill pipe can be displayed, and when desired, individual frequencies or narrow bands of frequencies can be isolated, displayed, recorded, and/or measured.

In the normal course of drilling oil wells with a rotary rig, for example, the wells are frequently on the order of 10,000 or more feet deep. Even when a rotary gear type tool is utilized on the end of the drill pipe string, the frequency of the vibrations generated by the tool rotation at the bottom of the well cannot be satisfactorily isolated at the top of the drill pipe, as the background noise existing in the drill pipe, due to many noise producing factors (such as the pipe rubbing on the sides of the bore during rotation of the pipe), wholly masks the gear-ground contact frequency. For a distinct, recognizable acoustic signal to be present at the top of the drill pipe in condition to be isolated and measured, it is important that an acoustic oscillator, operating at a controlled frequency, be present at or near the well bottom. It is also highly important that no special pipe or power connection be required between the surface and the oscillator, as such arrangements are not favored by the drilling crew, and in addition, due to the distance between ground and tool, such special rigs are expensive.

In accordance with the present invention, acoustic oscillators are used at or near the drilling tool that are excited wholly by energy existing at or near the bottom of the well during the normal drilling procedure using standard rotary drill pipe tools and methods.

Such oscillators are preferably placed in a relatively short oscillator section 40 of drill pipe inserted in the drill collar just above the tool 10. Oscillators capable of being continuously excited by normal drilling conditions, and then modulated by a condition on which information is desired, are shown in Figures 2, 3, and 4. These oscillators and related equipment are carried by oscillator pipe section 40.

Referring first to Figure 2, this figure shows an oscillator excited by energy derived from the mud flow through the drill pipe.

Here, one or more apertures 41 are made in the inner wall 42 of the oscillator section 40, each aperture 41 opening into a resonance chamber 43 in the wall 42 extending to a spring mounted vibrating valve 44 in a mud outlet 45. 'Ihe mud under pressure inside the drill pipe.

Will be forced out through the vibrating valve 44 to vibrate the latter and then will join the rising mud flow on the outside of the drill pipe. The pressure available is the drop across the tool. The energy of the vibration will be high, the action being similar to the well-known water hammer phenomenon.v This chamber s changed in size by a movable piston 47 which is under the control of a member whose physical dimensions are changed by a condition existing at the bottom of the well, for example. A typical member of this type is a temperature responsive element 48 which changes length in accordance with temperature, this element being positioned to move piston 47.

Other resonant systems with differing resonant chambers and differing condition responsive devices can be arranged around in the wall 42 of the oscillator section 40. For example, such a system with its piston 47, in a resonant chamber 43a, controlled by a tool pressure responsive device is shown in Figure 2 as a tool end section 50 splined into the oscillator section and sprung apart by heavy spring 51. Piston 47 is attached to the tool end section 50 by a long piston rod 52. Compression of the spring 51 due to drill string weight will change the vibratory period of the resonance chamber 46 and connected oscillator 44. A torque responsive element and frequency control is shown in Figures 2a and 2b where the tool 10 is joined to the oscillator section 40 by a relatively long torque tube 55.

The wall 42 of `the oscillator section 40 is extended downwardly around torque tube 55, to approach a shoulder 56 on the tool 10. A connecting rod 57 is attached to a piston 47 and also extends downwardly through wall 42 to contact shoulder 56. At the point of rod-shoulder contact, the shoulder is angularly cut, as shown in Figure 2b so that any relative twist between walls 42 and the tool 10 will result in motion of rod 57 and piston 47 to change the frequency of the related oscillator 44.

When several oscillators are utilized in the oscillator section 40 the frequency bands thereof are spaced in the frequency spectrum so that they can readily be separated by the narrow band filters F and separately displayed.

'I'he oscillators just above described are energized by the mud flow. In Figure 3 we have shown diagrammatically oscillators operated by the rotation of the drill pipe.

` Referring now to Figure 3, a metal cylinder 60 slotted along its axis is attached to a shoulder 61 on the oscillator section 40 and extends downwardly and concentrically around a central portion 62 of the oscillator Section 40 to form a cylindrical oscillator. The frequency is determined by its density, elasticity, temperature, wall thickness and length.

The oscillator cylinder 60 is excited into vibration by a friction block 64 which is rotated by a free external collar 65 supported on a ball bearing 66 from the oscillator section 40. The collar 65 is provided with drag vanes 67 extending outwardly into the mud flowing upwardly around the oscillator section 40 of the drill pipe. The drag of the vanes 67 in the mud slows down rotation of the free collar so that the latter rotates much more slowly than the drill pipe, thereby causing the friction block 64 to act on steel cylinder 60 to set this oscillator into vibration.

If only temperature is desired to be transmitted by the oscillator 60, no modulating device is needed as the oscillation period of the cylinder will change with temperature. If it is desired to additionally change the period of the oscillator, the cylinder 60 can be provided with a closely fitting weight collar 70 slideable over the interior of the cylinder 60 under the control of a modulating rod 71. This modulating rod 71 can then be displaced in manners similar to those described in conjunction with piston movement in Figures 2, 2a and 2b. When modulated, cylinder 60 can be calibrated for temper-Y ature to give a temperature correction for modulation according to another condition or cylinder 60 can be made from temperature insensitive material as is well known in the art. Well bottom oscillators can also be excited by vibrations existing at or near the tool, as shown in Figure 4.

Here, the oscillator is a vibrating reed 74 in a cavity 75 in wall 42 having a Weighted head 76 positioned to strike anvils 77. As the resonant frequency of the reed 74 will depend on the length thereof, the length of the reed can be controlled by displacement as previously described. In the embodiment shown modulation is by a modulating rod 71.

The general band of frequencies at which reed 74 will oscillate is selected at points where strong local vibrations exist, such as, for example, frequencies close to the drill tooth contact frequency at a standard drilling rotational speed. The oscillator reed 74, tuned to this frequency, will be excited so that weight 76 will contact anvils 77, thereby creating a clear reinforced acoustic frequency in the drill pipe. Oscillators of this latter type are suitable for both lateral and longitudinal vibrations in accordance with the orientation of reed 74.

The clear, clean cut sound vibrations produced in the drill pipe by the oscillators described above are clearly distinguishable over the general noise level existing in the pipe, and the frequency variation produced by the various conditions that are monitored at the bottom of the well is readily read at the top of the well in terms of condition values. No special connection between top and bottom of the well is required, and there is no necessity for a power source to be installed in the oscillator section 40. There is no interference with the normal drilling operation and readings can be made at locations remote from the rig, and continuously recorded if desired.

From the above description it will be apparent that there is thus provided a device of the character described possessing the particular features of advantage before enumerated as desirable, but which obviously is susceptible of modification in its form, proportions, detail construction and arrangement of parts without departing from the principle involved or sacrificing any of its advantages.

While in order to comply with the statute, the invention has been described in language more or less specific as to structural features, it is to be understood that the invention is not limited to the specific features shown, but that the means and construction herein disclosed comprise the preferred form of several modes of putting the invention into effect, and the invention is, therefore, claimed in any of its forms or modifications within the legitimate and valid scope yof the -appended claims.

We claim:

l. An acoustical oscillator adapted to be positioned adjacent the lower end of a hollow drill pipe used in drilling a well comprising a length of hollow conduit adapted to be inserted in the lower end of said drill pipe for passage of drilling iluid therethrough, said conduit having a passageway from the interior of said conduit to the exterior thereof, a vibratory element in said passageway and shaped to be vibrated directly by passage of iiuid through said passage way, means defining a resonance chamber in the wall of said conduit and forming a part of said passageway, and means in said chamber for changing the volume of said resonance chamber, said latter means being connected to be moved by the value of a condition existing adjacent said conduit on which information is desired.

2. In a well drilling rig in which a tool is rotated at the bottom of the well through a hollow pipe extending above the ground and wherein a liquid is circulated downwardly underpressure through the interior of `said pipe to emerge therefrom at the lower end of said tool, means for obtaining information from the bottom of said well during the drilling thereof comprising means defining a passageway through the Wall of said pipe just above said tool whereby a portion of the liquid in the interior of said pipe passes through said passageway, a vibrator attached to the wall of said pipe in a position to be contacted by and directly vibrated by the flow of fluid through said passageway to impart an acoustical vibration to saidv pipe, a portion of said passageway being enlarged to form a resonance chamber controlling the frequency of vibration of said vibrator, a condition responsive device in the wall of said pipe adjacent said resonance chamber, means in said resonance chamber movable to change the volume thereof, said latter means being connected to said condition responsive means for movement thereby to change the the frequency of vibration of said vibrator, and means for receiving solely on said pipe, above ground level, the acoustical oscillation imparted to said drill pipe b-y said vibrator.

3. Apparatus in accordance with claim 2 wherein said condition responsive means is a temperature sensitive device.

4. Apparatus in accordance with claim 2 wherein said condition responsive device is a torque responsive device.

5. Apparatus in accordance with claim 2 wherein means are provided connected to said receiving means to isolate the frequency of said oscillator from other frequencies simultaneously existing in said drill pipe and for indicating a change in said frequency.

6. In a weli drilling rig in which a tool is -rotated at the bottom of the well through a hollow pipe extending above the ground and wherein a liquid is circulated downwardly under pressure through the interior of said pipe to emerge therefrom at the lower end of said tool, means for obtaining information from the bottom of said well during the drilling thereof comprising means defining a charnber in the wall of said hollow pipe just above said tool, said chamber being elongated in the direction of extent of said pipe, means defining a fluid inlet from the interior of said pipe to the interior of said chamber, means defining an outlet at the top of said chamber connecting the outside of said pipe to the interior of said chamber, a spring mounted valve in lsaid outlet at the top of said chamber and positioned to at least partially block fluid ow through said outlet to vibrate under fluid ow through said chamber and to impart vibrations to said pipe, a condition responsive device in the wall of said pipe adjacent said chamber, and means in said chamber movable to change the volume thereof, said latter means being connected to said condition responsive means for movment thereby, and means for receiving solely on said pipe, above ground level, the acoustical oscillation imparted to said pipe by said valve.

References Cited in the le of this patent UNITED STATES PATENTS 2,380,520 Hassler July 31, 1945 2,396,935 Walstrom Mar. 19, 1946 2,425,868 Dillon Aug. 19, 1947 2,524,031 Arps Oct. 3, 1950 

